Preparation and electromagnetic properties of multi-component absorbing agents and their double-layer coatings on polyester fabrics

As the electromagnetic environment in the natural environment becomes more complex, the demand for fabrics with microwave-absorbing function becomes more urgent. To meet this demand, a two-step hydrothermal method and coating were used to prepare and obtain a wave-absorbing functional polyester, which was tested and analyzed in terms of microscopic morphology and electromagnetic properties. The results show that the Co₃O₄/COOH@MWCNTs/NiFe₂O₄ composite prepared by the two-step hydrothermal method has excellent electromagnetic properties, and the polyester fabric treated with this composite as a wave absorber and aqueous polyurethane as a binder has excellent microwave-absorbing properties. It was concluded that when the fabric possessed a reflective layer, the concentration of the absorber was 10%, and the mass ratio of the absorber components, Co₃O₄: MWCNTs: NiFe₂O₄ = 6:2:1, the fabric showed the best performance in terms of wave-absorbing properties, at which time it had the largest reflection loss at 19.26 GHz, with a maximum reflection loss of − 22.7 dB and an effective absorbing frequency band of 13.46–20 GHz (6.54 GHz).